LMR36506-Q1: VIN and EN use case

Atsushi Hirai

Part Number: LMR36506-Q1

Hi, team.

My customer is considering to use this device with VIN=50V and EN=13V. Customer understand the switching frequency is folded back due to the high VIN voltage and it's no problem.

In their plan, EN will be forced before VIN input at the start up, and EN will be removed after VIN input. So the device starts and stops by UVLO every time.

Is there any concern for this usage? Please advice.

Regards,

over 4 years ago

0 Andy Chen over 4 years ago

TI__Mastermind 34875 points

Hi Hirai,

Do you mean customer wants the circuit to startup at Vin=3.5 and shutdown at Vin=3.0V?

If no other special power sequence control, then just connect the EN to VIN.

if EN signal is from other circuit/device and applied before VIN ramp up, then connect the control signal by 100K resistor to EN pin.

B R

Andy

0 Atsushi Hirai over 4 years ago in reply to Andy Chen

TI__Expert 4970 points

They want to use separate power rail for VIN and EN. And the EN signal is earlier than VIN ramp up and later than VIN ramp down. So the device starts and stops by UVLO. not EN.

Okay, I'll comment that there is no concern if they put 100kohm at EN signal in series.

+1 Andy Chen over 4 years ago in reply to Atsushi Hirai

TI__Mastermind 34875 points

Let's discuss it in email.

I will close this thread.

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LMR36506-Q1: VIN and EN use case